Prevailingly to substantially atactic crude polymers and methods for producing the same



United States Patent 3,261,820 PREVAEHNGLY T0 SUBSTANTIALLY ATACTTC CRUDE POLYMER AND METHODS FQR Pitt D-UQENG THE SAME Giulio Natta, Piero Pine and Giorgio Mazzanti, all of Milan, taly, assigners to R'lcntecatini Societal Generaie peg lindustria Mineral-la e Elhirnica, a corporation of 1:21 y No Drawing. @riginal appiication Nov. 22, 1955, Ser. No. 550,154. Divided and this application Aug. 7, 1958, Ser. No. 753,624 Elairns priority, application Italy, Dec. 3, 1954, Patent 526,101; Dec. 16, 1954, Patent 545,332 14 (Claims. ((11. 260-935) This is a division of Serial No. 550,164 filed November 22, 1955, and now abandoned.

This invention relates to a new process for the selective polymerization of certain unsaturated hydrocarbons. More particularly, the invention relates to a process for producing, at will, polymers of unsaturated hydrocarbons which are made up predominantly (for more than 50%) of linear, regularly head-to-tail vatactic macro-molecules.

The unsaturated hydrocarbon polymerized has the formula CH =CHR in which R is a saturated aliphatic, an ialicyclic or an aromatic radical. The unsaturated hydrocarbons may be polymerized alone or in admixture with one another, or in mintures with small amounts (l15%) of another monomer copolymerizable therewith. In the formula given, R may be in specific modifications, an alkyl, cycloalkyl or :aryl radical.

One object of the invention described and claimed herein is to provide a new process for polymerizing the unsaturated hydrocarbons whereby it is possible to obtain, at will, polymers having a predetermined, prevailing proportion of amorphous macromolecules.

Another object is to provide an improved method for polymerizing the unsaturated hydrocarbons wherein the polymerization is carried out in the presence of and with the aid of a polymerization catalyst in a predetermined state of aggregation and predetermined state of dispersion such that the mechanism of the polymerization is influenced and polymers having a predetermined, prevailing content of amorphous macromolecules are selectively produced.

In our Italian Patents Nos. 535,712 granted Novembet 8, 1955, and 537,425, granted December 28, 1955, on, respectively, our Italian applications Nos. 24,227 filed June 8, 1954, and 25,109, filed July 27, 1954, we have described new, regular, linear head-toata-il polymers of the unsaturated hydrocarbons as well as an improved method for producing the same.

The method described in Italian Patent No. 537,425 involves the use of polymerization initiators or catalysts as described by Professor Karl Ziegler, in German application Serial No. Z 4,348, filed August 3, 1954, for the polymerization of ethylene to polymers of high molecular weight, the priority of said German application being claimed in the Ziegler et al. patent No. 3,112,115 issued December '3, :196 3, and a copy of said German application and English translation thereof being available in the file of U.S.P. 3,112,115.

Those catalysts are prepared by reacting a catalytic heavy metal compound and a catalytic metal alkyl compound together in the dissolved state.

The catalytic metal alkyl compound used in preparing the catalyst comprises a substance or mixture of substances consisting of simple and complex compounds the molecules of which contain as a central atom an 3,261,820 Patented July 19, 1956 element from the second and third columns of the Periodic T able, i.e., beryllium, magnesium, zinc, cadmium, and other elements of the second group, and aluminum and other elements of the third group.

The valences of the aforesaid central atom are linked to the same or different alkyl and alkoxy radicals such as ethyl, propyl, butyl, ethoxy, etc. One valence of the central atom may be satisfied by halogen.

The catalytic heavy metal compound used in the preparation of the catalyst consists of a compound or a mixture of compounds of a heavy metal of the first subgroup of groups IV to VI of the Periodic Table, including thorium and uranium, i.e., compounds of the elements of titanium, zirconium, hafnium, thorium, vanadium, tantalium, niobium, chromium, molybdenum, tungsten and uranium.

We have found, further, as set iorth in our Italian Patent No. 537,425, that the polymerization agents are particularly eflicient when prepared in the presence of the free unsaturated hydrocarbon to be polymerized.

As disclosed in our said Italian patents the crude (total) polymerizates of the unsaturated hydrocarbons produced with the aid of the catalysts prepared as described above are, initially, mixtures of linear, head totaril polymers having substantially no branches longer than R. The mixtures comprise, mainly, amorphous and crystalline macromolecules in varying amounts.

Depending on their steric structure and molecular weight, these polymers (macromolecules) exhibit very different characteristics. The amorphous polymers have viscous elastic properties which lie between those of a highly viscous liquid and those of an unvuleanized, non-crystallizable elastomer, while the solid, highly crystalline polymers, which can be oriented by drawing, are fiber-forming.

The polymerizates we obtain, which are mixtures of linear, head-totail amorphous and crystalline macromolecules having no branches longer than R are unique in this art. That both types of polymers are linear is shown by their infrared spectra. For example, in the case of our polypropylene, both the amorphous and crystalline polymers have similar inira red spectra which are completely different from the infrared spectra of the known branched polypropylene in which the branches are longer than R.

When monomer units some of which contain an asymmetric carbon atom having an I configuration and some of which contain as asymmetric carbon having a d configuration recur statistically along the polymer chain, as is the general case for all known vinyl polymers, the polymer may be considered as a copolymcr of the two types of structural units. If the substituent R is much larger than an H atom, the polymer (or copolymer in the sense just explained) is substantially non-crystalline and does not have any first order transition temperature.

Prior to our work, the only known example of a vinyl polymer existing in both an amorphous and in a crystalline form were the polyvinyl ethers prepared by Schildknecht and co-workers (Ind. Eng. Chem, 40 (1948), 2104; ibid., 41 (1949), 1198, 2891). Those polyvinyl others are, of course, quite dilierent from the polymeric products we have disclosed.

When all the R groups of a plurality of chains show the above-mentioned regular arrangement, the polymers tend to adopt a crystalline structure. This is confirmed by examination with X-rays. We shall refer to the regular enchainment of the asymmetric carbon atoms in the main chain, which is a basic condition for crystallinity of our polymers, as isotactic.

Our linear regular head-to-tail macromolecules having substantially no branches longer than R and the main chain of which has substantially a structure of the kind illustrated in the model below (isot'actic structure):

(Model of a portion of the main chain of a crystalline polyalpha-olefin according to the present invention, arb trarily fully extended in a plane in which model the R substltuents on the tertiary C atoms are all above and their H atoms below the plane of the chain.)

are recognized in the art (following us) as isotactic macromolecules, whereas our macromolecules having substantially no branches longer than R and in which the asymmetric carbon atoms of the two possible steric configurations have a substantially random distribution along the main chain are recognized in the art (following us) as linear, regular head-to-tail atactic macromolecules.

We have adopted the new term isotactic for identifying the structure of the kind shown in the model, the macromolecules having substantially that kind of structure, and polymers consisting of these macromolecules substantially having that kind of structure (see, for example, the Natta et al. communication to the Editor of the Journal of the Amer. Chem. 800., published in said Journal on March 20, 1955, received for publication December 10, 1954; the Natta article published in the Journal of Polymer Science, April 1955, vol. XIV, issue No. 82, pp. 143154, received for publication on February 17, 1955, U8. Patent Nos. 2,882,263, 3,112,300 and 3,112,301).

The main chain, when in the crystalline state, assumes a coiled configuration, the spiral having a pitch corresponding to a definite number of monomer units, generally three. In such case, all bonds between the R groups and the main chain have the same angle of inclination relative to planes perpendicular to the axis of the spiral.

On the other hand, whenever the polymerization leads to a random distribution of the orientation of the side chain in relation to the plane of the main chain, an amorphous product results.

If the side chains, i.e., the groups R, are of considerable length compared with the distance of the carbon atoms in the main chain from one another, and if they possess a great mobility, said chains will obstruct the arrangement of a plurality of chains to form a crystal. The melting point of the crystalline polymers of the linear alpha-olefines generally decreases by increasing length of the R groups. Polymers containing isotactic chains generally show, besides a tendency to crystallize, also greater density, higher softening or melting temperature and lower solubility, compared with the nonisotactic products of equal molecular weight.

If the arrangement of asymmetric carbon atoms is isotactic crystallinity of the polymers occurs already at relatively low molecular weights, e.-g. from about 1000 upward.

Although we were able to produce the polymerizates comprising the mixtures of sterically differentiated amorphous and crystalline macromolecules from the unsaturated hydrocarbons using the catalysts described above, no method was available for steering the polymerization so as to predetermine the ratio of amorphous to crystalline macromolecules in the polymerizate. Such steering is accomplished by the process of the present invention according to which polymers of preselected character, and being predominantly to exclusively made up of the atactic, linear, regularly head-to-tail amorphous macromolecules, can be obtained at will.

The present process is based on our discovery that the higher alpha-olefins can be polymerized directly to a crude polymerizate made up for more than 50% of linear, regularly head-to-tail atactic polymers (macromolecules) by contacting the alpha-olefin, in a hydrocarbon polymerization medium, with a catalyst consisting essentially of the substantially non-crystalline portions that are finely dispersible in the hydrocarbon medium of the catalytic system obtained by starting with a compound of a transition metal of Groups IV to VI of the Mendeleeff Table, and of the type of the hydrocarbon-soluble halides, oxyhalides and alkoxyhalides of the metals, and mixing said compound with an organ-ometallic compound of an element from the second and third columns of said table, the valences of which central atom are linked to the same or difierent alkyl radicals and one valence of which may be satisfied by an alkoxy radical, or by halogen.

Other factors to be taken into consideration in the process of the invention for selectively polymerizing unsaturated hydrocarbon so as to control the course of the polymerization and steer the same to obtain the polymerizates made up prevailingly of the linear, regularly head-to-tail, amorphous macromolecules will become apparent from the detailed discussion of the invention which follows.

The proportion of amorphous polymers in the polymerization products increases if a heavy metal atom in the heavy metal compound is of maximum valence and increases further with increasing dimensions of the anionic groups contained in the heavy metal compound.

The chemical nature of these anionic groups has also a considerable influence. Heavy metal compounds which, by reacting with the metal-alkyl compounds, give amorphous products that are easily dispersible in the reaction medium result in catalysts which favor the production of polymers of the unsaturated hydrocarbons richer in atactic macromolecules.

When compounds containing groups of various kinds bound to the Ti atom such as the Ti(OR),,Cl compounds are reacted with metallo-organ-ic compounds, the resulting polymerization agents are generally of less regular SllI IIOUHIB and lead to polymerizates consisting predominantly of non-isotacti-c (atactic, linear, regularly head-to-tail) macromolecules.

Considering, for example, a heavy metal compound wherein titanium represents the heavy metal, the following Table I will show that, starting with titanium tetrachloride 'as the highest stage of valence and ending with compounds containing large anionic groups such as (OH), or (OR).,, a whole scale of heavy metal compounds is available which permits of the selection of a compound which, when used for preparing the polymerization agent, will yield a polymerizate having a predetermined content of amorphous polymers (macromolecules).

Titanium tribromide even though it is a crystalline solid, yields, as compared to titanium trichloride, a larger proportion of non-isotactic polymers. This is due to the fact that TiBr is slightly soluble in the hydrocarbon solvent used, and therefore reacts with the metallo-organic compounds, at least in part, in a state of noncrystallinity, namely while being dissolved in the hydrocarbon.

Titanium tetrabromide behaves similarly to the tetrachloride, yielding a polymeriza-te made up partially of the amorphous and partially of crystalline macromolecules. The high melting point of TiBr has practically no influence since under the reaction conditions it is completely soluble in the solvent used.

Predominantly or wholly amorphous polymers are obtained with catalysts prepared by using as the heavy metal compound substances such as vanadium oxytrichloride (VOCl or vanadium tetrachloride, wherein vanadium is pentaor tetravalent, respectively, zirconium tetrachloride, chromium oxydichloride CrO Cl and the corresponding compounds of the other aforesaid heavy metals.

In general, it can be stated that if the heavy metal compound is soluble or partially soluble in the liquid medium in which the catalyst is prepared, the catalyst will tend to disperse readily in the polymerization medium and will favor the production of polymerizates of the unsaturated hydrocarbon made up prevailingly (over 50%) of the amorphous, ata-ctic, linear regularly headto-tail macromolecules. The medium in which the catalyst is prepared and the polymerization medium may be the same, i.e., the liquid monomeric unsaturated hydrocarbon to be polymerized, with or without admixture with a solvent for the metal alkyl compound which solvent does not enter into the polymerization reaction.

The following hypothesis of the mechanism of the reaction which, we believe, is taking place in the formation of the catalyst from the heavy metal compound and the metal alkyl component, and the subsequent polymerization of the unsaturated hydrocarbons with the aid of the resulting catalyst, is postulated as an explanation of the nature or mechanism of the process of our invention.

According to a preferred embodiment, the metal alkyl compound, such as aluminum triethyl, is dissolved in the unsaturated hydrocarbon to be polymerized and the heavy :metal compound, such as liquid titanium tetrachloride, is then brought into contact with the metal alkyl component in the presence of the olefine and the following react-ion will take place:

It was found that a mixture of amorphous macromolecules and crystalline macromolecules can be obtained from unsaturated hydrocarbons by using the unfractionated polymerization agents which are obtained by using I a preferably soluble or liquid heavy metal compound, such as titanium tetrachloride, titanium tetrabromide, vanadium tetrachloride and the like.

If such heavy metal compounds are reacted with a metal alkyl component, a change of valence will take place in the heavy metal compound. In the case of titanium tetrachloride, this change of valence can be assumed to take place according to the following scheme:

6 lyst, metal alkyl components in which the alkyl groups exhibit strongly lyophilic properties.

The presence of the latter groups in the final catalyst assists the formation of a colloidal dispersion of the latter in the solvent.

Lyophilic groups suitable for this purpose are, for instance, alkoxy radicals or alkyl groups having relatively long chains of carbon atoms, which can be introduced into the final catalyst by being previously bound either to the initial heavy metal compound or to the metal alkyl compound. Such groups should have more than four and preferably from six to sixteen carbon atoms.

In the following examples, the results of a number of polymerization tests are compiled which show the influence of such lyophilic groups in the metal alkyl :component of the catalyst on the proportion of amorphous polymers in the final polymerizate.

All tests reported in the examples were performed under comparable conditions. The molar ratios between titanium tetrachloride and the aluminum alkyl compound were in the order of 1:2.5 to 1:10.

It is apparent, from these examples, that the percentage of amorphous polymers in the final polymerization product increases with an increasing number of carbon atoms in the alkyl groups linked to aluminum, beginning with a number of 2 C atoms in the alkyl radical.

With the solutions or high-degree dispersions obtained when lyophilic groups are present in the initial heavy metal compound or in the metal alkyl component, no precipitate can be isolated by mechanical steps such as filtration and the like.

As can be seen from the examples the formation of a non-crystalline catalyst and its dispersion are also favored by using heavy metal compounds having alkoxy substituent groups even of relatively short length of chain. For instance, dibutoxy titanium dichloride Ti(OC H Cl also leads to the formation of a catalyst which yields predominantly amorphous polymerizates of the unsaturated hydrocarbons.

The examples show that the above mentioned rules for steering the polymerization process to obtain products of more or less predominantly amorphous character also prevail in the polymerization of the higher alphaolefines, such as butene-l.

It can be seen from the pertinent examples that the ratio of crystalline to amorphous solid polybutene-l is relatively high when using TiCl The influence of the length of the alkyl radical in the aluminum alkyl con.- pound is less pronounced than in the polymerization of propylene.

The examples also illustrate the influence of the presence of halogens as well as isoalkyl groups in the metal organic component in the composition of the final polymerization products. The presence of such halogen substituents in the metal organic component tends to increase the amorphous fraction of the final product, over that in the product obtained with the corresponding metal organic component containing only straight chain alkyl groups, while isomery does not change the ratio in the polymer.

As has been stated above, we have further discovered that the state of aggregation or the phase in which the finally obtained catalyst is brought into contact with the unsaturated hydrocarbon monomers to be polymerized if of considerable importance in controlling the formation of a polymerizate having a high content of amorphous macromolecules.

If the surface structure of the catalyst particle is irregular, as in a micellar dispersion in a liquid, such catalysts act as polymerization agents which yield nonisotactic and correspondingly amorphous polymerization products.

This is confirmed by a study of examples given which shows the influence of the halogen linked to the heavy metal in the heavy metal compound, when the heavy metal is in the maximum state of valence. It is apparent from the examples that in the case of bromide and iodide as the starting heavy metal component a change of valence from 4 to 3 does not result in increased crysfilter having pores of to 15 microns diameter. Catalyst particles which pass through such pores yield predominantly to exclusively amorphous polymers.

As shown in Table 2 below, in the case of catalysts tallinity in the resulting polymer but that the state of dis- 5 obtained from TiCl the fraction remaining on the filter persion of the polymerization agent in the reaction mecan be used as a catalyst for producing polymerizates diurn is the decisive factor. Thus the polymerization of higher (54%) crystalline polymer content than is conagent obtained with TiI yields a lower content of crystained in polymerizates produced with the aid of the untalline polymer than Til because it is more finely disfractionated catalyst. The latter polymerizates have a persed in the reaction medium than the polymerizing 10 crystalline polymer content of only about 40%.

agent obtained from the latter substance.

In the case of TiBr the two factors, valence and state fii fg 35 g gfi, i%%ggg EREPQZEQ of dispersion, balance each other, so that the degree of or CATALYST PREPARED FROM HEAVY METAL TET- crystallinity obtained in the final polymerization is the RAHALIDE AND ALUMINUM TRIETHYL same.

The influence exerted by the nature of the polymeriza- Polymenzaflon Agent- 'gg g styrene gfiij tron aid or catalyst in the polymerization of the unsaturated hydrocarbons or alpha-olefines can be explained Pmcipiwte (5O) (53) 1n the following manner: 53.7 as

We have made the discovery that a titanium contain- Film, 1(51) 1 (54) ing catalyst or a catalyst containing another heavy metal of the kind described, of maximum valence, prepared as Unfmctwnated (9) 418 described in our Italian Patent No. 537,425 and comprising both coarse crystalline particles and finely dislcompletely amorphous persed to dissolved or liquid portions can be separated into several fractions one of which comprises a micellar Other known separation methods, e.g., decantation, dispersion or finer, less crystalline particles which yield flotation or centrifuging may be used to separate the more predominantly or exclusively amorphous, non-crystalcrystalline (generally heavier) portions of the catalyst lizable polymeric products, i.e., polymers having mainly from the amorphous (generally lighter) portions thereof. non-isotactic chains. It Will be apparent that the present invention provides As described in said Italian Patent No. 537,425 when methods for preparing various catalysts which can be the unfractionated catalyst is used, a mixture of amorused selectively for the production of mixtures having phous and crystalline polymers is obtained. However, a predetermined content of crystalline to amorphous when the coarser, more crystalline particles are separated, polymers; or substantially completely amorphous polyfor instance by filtering the catalyst containing medium mers of the unsaturated hydrocarbons. through filter plates having relatively small pores, the Tables 3, 4 and 5 illustrate the various aspects of our filtrate containing the finer, more highly dispersed parinvention as applied to various heavy metals of the groups ticles can be used as aid in the selective polymerization described above, other than titanium. These tables conof the unsaturated hydrocarbons to substantially comfirm the influence of the various factors explained hereinpletely amorphous products. This separation is accomplished, for example, by the use of a porous glass plate above, using heavy metal compounds other than titanium compounds.

TABLE 3..DEGREE OF CRYSTALLINITY OF PROPYLENE AND BUTENE-1 POLYMERS OBTAINED \VIIII VARIOUS HEAVY METALS OF DIFFERENT VALENCY, AND WITH DIFFERENT METAL ALKYL COMPOUNDS Propylene polymerization Butene-l polymerization T101 ZrCh V014 V001; CrCl AlEthyh (9) (40) (35) (36) (37) (44) Al Iropyl (10) (46) A1 Dccyl;

AlHexadccyl 13 TABLE 4.-DEGREEOF ORYSTALLINITY IN PROPYLENE POLYMERS OBTAINED \VITH POLYMERIZATION AGENT PREPARED FROM HEAVY METAL HALIDES OF DIFFERENT VALENCES AND ALU- MINUM TRIETHYL TABLE 5.-DEGREE OF CRYSTALLINITY IN BUTA-NE-l P O L Y M E R S OBTAINED WITH POLYMERIZATION AGENT PREPARED FROM HEAVY METAL HALIDES 1011 DIFFERENT VALENCES AND ALUMINUM TRI- THYL It may be noted that the use of alkyl-aluminum compounds containing alkyl groups of high molecular weight has a considerable influence in reducing the molecular weight of the polymer, when TiCl is used. In that case, the alkyl groups of high molecular weight have an anticoagulating etfect on the catalyst which is formed. When solid TiCl is used, the anti-coagulating effect is not exhibited.

The following examples illustrate in detail certain specific embodiments of the invention and explain the manner in which the above tables have been obtained, it being understood that these examples are not intended as restrictive of the scope of the invention.

Example 1 About 600 ml. of solvent (heptane-isooctane mixture) containing 11.4 g. triethylaluminum are introduced into a 18/8 stainless steel autoclave of 2150 ml. capacity. 325 g. of propylene are added and the mixture is heated up to 60 C.; then 3.6 g. titanium tetrachloride dissolved in 50 ml. solvent are admitted into the autoclave. The temperature rises spontaneously in a few minutes up to 113 C. and then slowly decreases. When the temperature reaches 80 C., 1.8 g. titanium tetrachloride dissolved in 50 ml. gasoline are added. A further smaller temperature increase is then observed. The autoclave is kept in agitation for about two hours. It is cooled then to 60 C. and the residual gases are released.

The polymerizing agent is decomposed by introducing into the autoclave 150 g. of methanol. After stirring for a few minutes, the reaction product, consisting of a solid mass drenched with methanol and gasoline, is discharged. The product is slurried in ether and treated with hydrochloric acid to remove most of the inorganic substances, and is then coagulated with methanol and filtered. Thus 282 g. of a white solid product are obtained having a softening point of about 130-140 C. The yield of solid polypropylene on the introduced propylene is 87%; the yield on the converted propylene is higher than 95%.

The polymer obtained is fractionated by hot extraction with solvents, using, successively, acetone, diethyl ether and n-heptane.

The acetone extract corresponds to 40.5% of the poly- 'mer obtained and consists of a rubbery, amorphous solid.

In tetralin solution at 135 C. it shows an intrinsic viscosity equal to 0.49 (corresponding to a molecular weight of 11,000).

The heptane extract corresponds to 24.4% of the polymer obtained and consists of a partially crystalline solid having an intrinsic viscosity equal to 0.95.

The residue which remains after said extractions amounts to 27.2% of the total polymer and consists of a powdery, highly crystalline solid having a first-order transition point of about 160 C. In tetralin solutions at 135 C. it shows an intrinsic viscosity equal to 1.77 (corresponding to a molecular weight of about 78,000).

Example 2 530 ml. of gasoline containing 15.6 g. tripropyl aluminum and 275 g. propylene are introduced into a 2150 ml.

autoclave, which is then heated up to 70 C. Thereafter, 3.6 g. titanium tetrachloride dissolved in gasoline are added. The temperature rises spontaneously to 95 C., then drops down again to C. A further addition of 1.8 g. titanium tetrachloride is made. The autoclave is then kept in agitation for four hours while keeping the temperature at 80 C. By operating as in Example 1, 209 g. of solid polymer are obtained. The purified, unfractionazted polymer begins to soften at 140 C. The yield is 76% on the introduced propylene, and higher than on the converted propylene.

The acetone extnact corresponds to 7.1% of the polymer obtained and consists of oily, low molecular weight products.

The ether extract corresponds to 32.4% of the polymer obtained and consists of a rubbery, amorphous solid having an intrinsic viscosity of 0.9.

The heptane extract corresponds to 19.1% of the polymer obtained and consists of a partially crystalline solid having an intrinsic viscosity of 0.95.

The residue which remains after said extractions corresponds to 41.4% of the polymer obtained and consists of a powdery solid product which appears highly crystalline. When examined under the X-rays, it has an intrinsic viscosity of 4.6 and becomes soft at about 180 C. The mechanical properties of samples obtained from such products are, due to the higher viscosity, better than those of samples obtained by the procedure described in Example 1.

Example 3 A solution of 10 g. Al(nC H in 150 ml. n-heptane is introduced into a ml. autoclave; 200 g. of a propylone-propane mixture, with 92% propylene, are then added. After heating the autoclave to 73 C., a solution of 3.8 g. TiCL, in 20 ml. n-heptane is injected.

The temperature rises spontaneously to 95 C., while the pres-sure falls rapidly. A finely dispersed polymerization catalyst is formed.

The autoclave is kept in motion for about 4 hours at temperatures between 80 and 90 C. Methanol is then pumped in the autoclave, and, after purification in the usual way, 80 g. of solid, white, polypropylene are obtained, which is then fractioned by extraction with hot solvents.

The raw polymer had therefore a crystallinity of about 30%.

Example 4 A solution of 28.2 g. of mole) of a trialkyl aluminum, having an average molecular weight corresponding to trihexylaluminu-m, is introduced into a 2150 ml. stainless steel autoclave, previously dried and evacuated. 28.5 g. of liquid propylene are admitted. then the autoclave is put in motion and the heating started. Once the temperature of 80 C. is attained, a solution of 3.8 g. TiCl in 40 ml. heptane is introduced in the reaction vessel. The temperature goes up spontaneously reaching in a few minutes C., and then drops slowly again. When the temperature is down again to 80 C., 3.8 g. more of TiCl dissolved in 40 ml. heptane, are added. A further temperature increase occurs although smaller than the previous one. The autoclave is shaken for 2 more hours, the gaseous products are then vented and finally about 100 ml. methanol are introduced in order to decompose the polymerization agent. The residual gases derived from the decomposition of the catalyst are released; in the autoclave remains a viscous solid mass, which is discharged and purified by heating with ether and hydrochloric acid in order to remove the inorganic substances present on the filter, resulting from the decomposition of the catalyst. The polymer swollen by sa1d solvents is then coagulated with methanol, filtered and washed with methanol. The solid mass left on the filter is then dried under reduced pressure at a temperature below 100 C.

25 g. of polymer are thus produced, corresponding to an 87% conversion of the employed propylene. 73.8% thereof is made up of an amorphous polymer, most of which, soluble in warm ether, shows the properties of an unvulcanized elastomer. The ether-soluble portion when extracted with warm acetone leaves an extraction residue having a softening point of 75 C., an intrinsic viscosity of 0.33 (determined in tetralin solutions at 135 C.) and a molecular weight of about 7,000.

The remaining 26.2% is formed of crystalline polypropylene, the bulk of which is insoluble in hot n-heptane,

has a softening point of 150 C., an intrinsic viscosity of 1.28 and a molecular weight of about 50,000.

Example 5 Proceeding as in Example 4, 70.2 g. of a trialkylaluminum having an average molecular weight corresponding to trihexadecylaluminum dissolved in 500 ml. heptane, and 350 g. liquid propylene are introduced into a 2150 ml. autoclave. The autoclave is heated up to 67 C. while keeping it in agitation; the solution of 3.8 g. titanium tetrachloride in 40 ml. heptane is then injected under nitrogen pressure. The temperature goes up spontaneously to 110 C.

Once the temperature is down again to 100 C. a solution of 3.8 g. titanium tetrachloride in 40 ml. heptane is injected. About 5 hours from the start of the polymerization 100 ml. methanol are pumped into the autoclave and the residual gases are vented.

Operating as in Example 4, the catalyst is decomposed and after purification 338.7 g. of a solid polymer (corresponding to 96.5% of the employed propylene) are separated.

The raw product is made up mostly (83.8%) of amorphous polymer and only 16.2% is crystalline polypropylene, which may be separated from the remaining polymer by means of successive extractions with' acetone,

ether and n-heptane.

The amorphous portion, insoluble in acetone and soluble in ether, shows a softening point of 70 C., an intrinsic viscosity of 0.5 and a molecular weight of about 11,000. The crystalline portion, insoluble in n-heptane, has a softening temperature of about 150 C., an intrinsic viscosity of 1.03 and a molecular weight of about 37,000.

Example 6 A sealed glass vial containing 9 g. dichlordibutoxy titanium (TiCl (OC H and 3 steel balls are intro duced into a 2150 ml. autoclave. Under nitrogen atmosphere the solution of 11.4 g. triethylaluminum in 500 ml. heptane is then syphoned in the autoclave. After heating up to 80 C., 275 g. of liquid propylene are then added and soon afterwards the autoclave is put in motion,

.made up of amorphous polypropylene, mostly soluble in warm ether.

The remainder (35.1%) is crystalline polypropylene, which may be separated from the amorphous portion by means of successive extractions with solvents.

Example 7 Into an autoclave of about 2 liter capacity are introduced under nitrogen a solution of 11.4 g. triethylaluminum in 500 cmfi heptane and 190 g. propylene. The autoclave is heated to 64 C. and at this temperature a solution of 0.03 mole titanium tributylate monochloride in 50 cm. pentane is injected under nitrogen pressure. The autoclave is kept in motion for about 8 hours at a temperature between and C. After this time the reaction product is taken out; after purification and drying there are obtained 8 g. of a solid, gummy, polymer containing approximately 10% of crystalline polypropylene.

Example 8 Example 7 is repeated, using titanium tetrabutylate instead of the tributylate monochloride, 5.4 g. of low molecular weight polypropylene are obtained, which contain only traces of crystalline polymer.

Example 9 Percent of Intrinsic the total viscosity Remarks polymer Acetone extract 60 Amorphous. Ether extract 33 0.37 Solid amorphous. n-Heptane extract 6 0.71 50% crystalline. Residue 1 Highly crystalline.

The obtained polymer had therefore a crystallinity of about 4% Example 10 A glass vial containing 9.5 g. titanium trichloride is introduced together with 3 stainless steel balls, into a 2150 ml. autoclave. A solution of 11.4 g. triethylaluminum in 300 ml. heptane is then added under nitrogen atmosphere. The autoclave is heated to 70 C. and 202 g. butylene, prepared from butyl alcohol and containing 70% butylene-l and 30% butylene-Z are introduced. The autoclave is kept in agitation at temperatures between 7880 C. for 20 hours. Methanol is then pumped in and the unreacted gases are discharged.

From the autoclave a very viscous mass is discharged, which is entirely coagulated by further addition of methanol and purified as usual. 29 g. of white solid polymer are obtained, which are fractionated through extraction with hot solvents. 65% of the product is crystalline polybutylene of a molecular weight above 30,000.

The remainder is formed of wholly amorphous product showing the properties of an unvulcanized elastomer.

When the run is repeated employing as a catalyst a mixture of TiCl and trihexadecylaluminum, a viscous product is obtained which is more fluid than the one of the preceding case, and formed in practice wholly by amorphous polybutene.

Example 11 6.5 g. TiCl in a glass vial and two steel balls are introduced into an oscillating 1100 ml. autoclave. The autoclave is filled with nitrogen and a solution of 19.8 g. Al(n-C H in 500 ml. n-heptane is then added. After acenezo 13 heating to 85 C., 115 g. butene-l (Phillips pure grade) are added and the autoclave is put in motion so as to break the vial.

The temperature rises rapidly to 95 C. After keeping the autoclave in motion for 4 hours, the polymerization product is taken out and purified as usual. 109 g. white, solid, polybutene of fibrous appearance are obtained, which are fractioned by extraction with hot solvents. The fractions are as follows:

Percent Intrinsic total viscosity Remarks polymer Acetone extract 3.1 Low oily polymers. Ether extract 29. 2 0. 82 Amorphous solid.

.7 2.12 Crystalline.

n-Heptane extract tttt 67 Example 12 Percent total polymer Remarks Acetone extract 3 Low molecular weight amorphous polymers.

42 Solid amorphous polymers.

55 Highly crystalline polymers soluble in hot n-heptane.

Ether extract Extraction residue"...

Example 13 160 ml. of gasoline containing 5.7 g. of triethyl aluminum, and 85 g. of butene-l (Phillips Petroleum Co. technical grade) are introduced into a 435 ml. autoclave. The autoclave is heated to 81 C. and 1.8 g. of titanium tetrachloride dissolved in 35 ml. of gasoline are then added. A spontaneous temperature increase of some degrees occurs.

After about one hour a further addition of titanium tetrachloride dissolved in gasoline is made; a spontaneous temperature increase of about C. occurs. The autoclave is kept in agitation for some hours at a temperature of 9098 C.

Operating as in the foregoing examples, 10 g. of a white solid product are obtained, which softens at 110 C. and appears crystalline under the X-rays. The residue of the extraction with ether corresponds to 46% of the obtained polymer and shows an intrinsic viscosity, calculated from measurements similar to those described in Example 1, of 1.44 ml./g.

Example 14 400 ml. of gasoline containing 11.4 g. of triethyl aluminum, and 291 g. of a butene-2-butene-1 mixture (with 70% of butene-l) are introduced into a 2150 ml. autoclave. The autoclave is then heated to 71 C. and 3.6 g. of titanium tetrachloride dissolved in gasoline are added; the temperature rises to 77 C. After two hours, a further addition of 3.6 g. of titanium tetrachloride is made. The autoclave is kept in agitation for some hours at a temperature in the range of 80-85 C. Operating as in the foregoing examples, 86 g. of white solid product are obtained. Said product shows characteristics similar to 14 those described in Example 13. Fibers are readily obtained from this product (the polymer mixture) by extrusion in a spinneret under nitrogen pressure at temperatures close to the softening point. They show a mechanical strength of the same order as the fibers obtained from polypropylene, but a higher elasticity.

The polymer mixture was fractionated, as in preceding examples, using hot solvents.

The acetone extract amounting to 14% of the total polymer, consists of oily, low molecular weight products.

The ether extract, which amounts to 35.5% of the total polymer obtained consists of a rubbery, amorphous solid having an intrinsic viscosity of 0.35, corresponding to a molecular weight of about 7,000.

The residue of the ether extraction is completely extractable with n-lieptane, with heating, and consists of a highly crystalline solid having a melting point of 125 C. and an intrinsic viscosity of 1.02, corresponding to a molecular weight of about 33,000.

Example 15 A solution of 8 g. tripropylaluminum in 90 ml. n-heptane and 47 g. butene-l (Phillips pure grade) are introduced into a 435 ml. autoclave.

The autoclave is heated to 65 C., and a solution of 3.8 g. titanium tetrachloride in 30 ml. n-heptane is injected under nitrogen pressure. The temperature rises spontaneously to about C. The autoclave is then kept in motion for about 5 hours, at temperatures between 75 and 85 C.

22 g. of a white, solid polybutene are obtained after purification in the usual way. It is fractionated by extraction with hot solvents, and the following results are obtained:

A solution of 19.8 g. Al(n-C H in 450 ml. n-heptane is introduced into a 1100 ml. autoclave filled with nitrogen. After adding g. butene-l (Phillips pure grade) the autoclave is heated to C. and at this point a solution of 7.6 g. TiCl in 50 ml. n-heptane is injected. The temperature goes up rapidly by about 10 while the pressure falls. The autoclave is then kept in motion for about 4 hours at temperatures between 85 and C.

After purification in the usual way the polymerization product yields 44.2 g. polybutene, which are fractioned by extraction with hot solvents, with the following results:

heptane, and 80 g. l-butene are introduced into an evacuated 435 ml. autoclave. After heating to 87 C. a solution of 2.3 g. TiCl in 30 ml. heptane is injected.

The autoclave is kept in motion for about 6 hours and, proceeding in the usual way, 60.5 g. polybutene are xtraction with hot Percent total Remarks polymer Acetone extract Ether extract n Heptane extract.-.

Example 18 500 ml. of gasoline containing 12 g. diethyl aluminum monochloride, and 310 g. of propylene are introduced into a 2150 ml. autoclave, which is heated to 60 C. Two portions of, respectively, 3.6 and 1.8 g. TiCl dissolved in gasoline, are then added. The reaction proceeds as described in the foregoing examples.

The reaction product consists of 248 g. of solid, white, polypropylene. The yield is 80% on the introduced propylene and about 95% on the converted propylene.

The acetone extract, consisting of oily products, corresponds to of the polymer obtained.

The ether extract, consisting of a rubbery, amorphous solid, corresponds to 44% of the polymer obtained and has an intrinsic viscosity of 0.4.

The heptane extract corresponds to 16.4% of the polypropylene obtained and consists of a partially crystalline solid with intrinsic viscosity 0.78.

The residue which remains after said extractions corresponds to 14.4% of the product obtained, has an intrinsic viscosity 1.53 and appears highly crystalline when examined under the X-rays.

Example 19 A solution of 19.8 g. Al(i-C H in 500 ml. n-heptane and 290 g. propylene are introduced into a 2150 ml. autoclave filled with nitrogen. After heating to 66 C., a solution of 7.6 g. TiCl in 80 ml. n-heptane is injected.

The temperature rises sharply to 95 C. After keeping the autoclave in motion for about 7 hours at this temperature, the product is taken out and purified as usual. 215 g. of solid polymer are obtained, which are fractionated by extraction with hot solvents.

The results of the fractionation are as follows:

The raw polymer had therefore a crystallinity of about Example Example 4 is duplicated, with the exception that a 435 ml. autoclave is employed, wherein 20 g. mole) of a dialkylaluminum monochloride having an average molecular weight corresponding to didodecyl aluminum monochloride, dissolved in 75 ml. anhydrous benzene, and 120 g. liquid propylene are introduced. The auto clave is heated up to 72 C., while agitating and then the solution of 1.9 g. titanium tetrachloride in 20 ml. heptane is injected under nitrogen pressure.

A spontaneous temperature increase of some degrees occurs. A solution of 1.9 g. titanium tetrachloride in 20 ml. gasoline is again injected. About 10 hours from the start, the catalyst is decomposed with methanol as in Example 4, and 68.5 g. of solid polymer are obtained, corresponding to a 57% conversion of the employed propylene. The polymer consists, practically in its entirety (more than 90%) of amorphous product.

The acetone insoluble and ether soluble portion of the amorphous polymer has a softening point of.55 C., an intrinsic viscosity of 0.25 and a molecular weight of about 5,000.

Example 21 3.4 g. titanium tribromide and a solution of 2.85 g. triethylaluminum in 100 ml. n-heptane are introduced into a 435 ml. autoclave. 115 g. of a propylene-propane mixture, with 91% propylene, are then added. The autoclave is heated to -90 C. and kept in motion for about 10 hours.

The polymerization product is purified as in the previous examples and gives 102 g. of a solid polymer, which is fractionated by extraction with hot solvents.

The acetone extract, 10% of the total, consists of oily, low molecular weight polymers. The ether extract, 36% of the total, is a solid, amorphous polypropylene.

The n-heptane extract, 20% of the total, has a crystallinity, as detected by X-rays measurement, higher than 50%.

The extraction residue, 34% of the total, crystalline polypropylene.

The obtained polymer had therefore a crystallinity of at least 44%.

is a highly Example 22 Two steel balls, a glass vial containing 13 g. of titanium tetrabromide and a solution of 11.4 g. of triethyl aluminum in 500 ml. of n-heptane are introduced under nitrogen into an autoclave of 1750 ml. capacity. The autoclave is heated, keeping it motionless, up to 63 C. and at this point 280 g. of propylene are introduced into the equipment. Soon afterwards the autoclave is put in motion, causing in this way the breaking of the vial. The temperature rises now spontaneously in a short lapse of time up to 97 C. and drops then again down to C. The autoclave is kept in agitation at this temperature for about ten hours. The unreacted gases are vented and methanol is pumped into the autoclave.

The polypropylene is then purified in the usual manner; 249 g. of polymer are obtained, equal to a conversion of 89% of the monomer employed.

The acetone extract corresponds to 15.1% of the polymer obtained and consists of oily products.

The ether extract corresponds to 33% of the polymer obtained and consists of a rubbery, amorphous solid with intrinsic viscosity 0.53.

The heptane extract corresponds to 22.1% of the polymer obtained and consists of a partially crystalline solid having an intrinsic viscosity equal to 0.65.

The residue which remains after said extractions cor responds to 30.8% of the polymer obtained and consists of a highly crystalline solid having, in tetralin solutions at 135 C., an intrinsic viscosity equal to 1.78.

Example 23 5.15 g. TiI and a solution of 2.85 g. Al(C H in ml. heptane are filled into a 435 ml. autoclave.

g. of a propylene-propane mixture, containing 91% propylene, are then added, the autoclave is heated to 85- 90 C. and kept in motion for about 20 hours.

The polymerization product appears as a semi-solid, tacky mass, which is purified and coagulated with methanol, 30 g. of solid, white polypropylene are thus obtained, while the evaporation of the solvent used in the polymerization and purification steps yields 54.3 g. oily, low molecular weight products.

Of the total 84.3 g. of product 64.5% is thus formed of oily products.

The solid polymer is fractionated by extraction with hot solvents. The amount of crystalline polypropylene thereby obtained is 10% of the total polymer.

Example 24 Two steel balls, a glass vial containing 17 g. of titanium tetraiodide, and a solution of 11.4 g. of triethyl aluminum in 500 ml. of heptane are introduced into an autoclave of 2080 ml. capacity.

The autoclave is heated to 71 C. and at this temperature 268 g. of propylene are introduced and soon afterwards the autoclave is put in motion, causing in this way the breaking of the vial. The temperature-rises spontaneously in a short lapse of time up to 100 C. and then drops again down to 90 C. The autoclave is kept in motion for about 6 hours and then the unreacted gases are vented, proceeding afterwards as described in the foregoing examples.

184 g. of propylene polymer are thus obtained which are fractionated by extraction with hot solvents.

The acetone extract corresponds to 20.4% of the polypropylene obtained and consists of oily, low molecular Weight products.

The ether extract corresponds to 22.7% of the polymer obtained and consists of an amorphous solid having, in tetralin solutions at 135 C., an intrinsic viscosity equal to 0.43.

The heptane extract corresponds to 22% of the polymer obtained and consists of partially crystalline solid with intrinsic viscosity 0.73.

The residue which remains after said extractions corresponds to 35% of the polymer obtained and consists of a powdery, highly crystalline solid having an intrinsic viscosity of 2.16.

Example 25 Into a 435 ml. stainless steel shaking autoclave are placed two steel balls (1 inch diameter) and a glass vial containing 4.3 g. (0.02 mole) VCl The autoclave is then closed and evacuated and a solution of 5.7 g. (0.05 mole) triethyl aluminum in 100 ml. n-heptane is then added under nitrogen pressure. The autoclave is then heated without shaking to 81 C., when 118 g. of pure liquid propylene are introduced. Thereafter the glass vial is broken by shaking the autoclave, which is kept in motion at temperatures varying from 81 to 83 C., while a regular pressure decrease (from 41 to 13 atrn.) is noticed. When a pressure decrease is no longer observed, methanol is pumped in the autoclave in order to decompose the catalyst. The autoclave is then vented and ml. of gas are collected. The reaction product appears as a solid, light green mass, drenched with heptane and methanol. In order to purify the polymer from the inorganic products, it is treated with ether and hydrochloric acid, then coagulated with methanol, filtered and washed with methanol. The obtained solid, white polymer is lastly dried by heating under reduced pressure. 77 g. of solid polymer are obtained, which corresponds to 65.2% of the used propylene. The obtained polymer is fractionated by extracting it in succession with hot acetone, ether and n-heptane.

The acetone extract, 10.1% of the total, consists of low molecular weight, oily polymers. The ether extract, 45.2% of the total, is a solid polypropylene, amorphous under the X-rays, with an intrinsic viscosity, in tetralin solution at 135 C., of 0.82, corresponding to a molecular weight of about 24,000. The heptane extract, 16.45% of the total, is a polypropylene having an intrinsic viscosity of 1.31, i.e., a molecular weight of about 50,000. This fraction is approximately 50% crystalline. The extraction residue is a highly crystalline polypropylene, with an intrinsic viscosity of 1.88. The raw polymer obtained has therefore a crystallinity of about 36%.

Example 26 A solution of 11.4 g. triethyl-aluminum in 400 cc. nheptane, and 350 g. of a mixture containing 82% propylene and 18% propane are introduced, under nitrogen into an autoclave of 2000 cc. capacity. The autoclave is heated under stirring to 80 C., and at this temperature a solution of 6.8 g. VOC1 in 100 cc. n-heptane is injected.

The temperature rises spontaneously to 87 C., while 18 the pressure falls rapidly. After about 5 hours methanol is pumped into the autoclave, and the polymerization product is taken out. The product is then purified from the inorganic compounds present by heating with ether and hydrogen chloride and complete coagulation with methanol.

172.5 g. polypropylene are obtained, corresponding to 60% of the used propylene. The polymer is then fractionated by extraction with hot solvents.

The acetone extract, 29% of the obtained polymer, is an amorphous, low molecular weight polypropylene.

The ether extract, 29.4% of the total, is an amorphous polypropylene with an intrinsic viscosity of 0.52.

The heptane extract, having a crystallinity of about 50%, shows an intrinsic viscosity of 1.15.

The extraction residue appears under the X-rays as a highly crystalline polypropylene, and has an intrinsic viscosity of 2.1. The raw polymer obtained had therefore a crystallinity of approximately 32.4%.

Example 27 Into a stainless steel shaking autoclave of 435 ml. capacity 2 stainless steel balls (1 inch diameter) and a vial containing 3.25 g. CrCl (i.e., 0.02 mole]: are introduced. Into the closed autoclave a solution of 5.7 g. (i.e., 0.05 mole) triethyl aluminum in 100 ml. n-heptane is added under nitrogen. The autoclave is then heated without shaking to C. and 115 g. pure liquid propylene are introduced. Soon after, shaking is started and continued at temperatures in the range 80 to 110 C.

Forty hours from the start the unreacted propylene is discharged. The reaction product is purified from the catalyst by washing with methanol and hydrochloric acid, and the solvents evaporated.

The obtained polymer is extracted with ether, which dissolves 37% of it; the dissolved fraction is completely amorphous. In the following extraction with boiling heptane a fraction corresponding to 44% of the total is dissolved, which is 50% crystalline and shows an intrinsic viscosity of 0.42.

The extraction residue is highly crystalline and has an intrinsic viscosity of 0.765. The raw product contains, therefore, approximately 41% crystalline polypropylene.

Example 28 5.7 g. triethyl aluminum dissolved in 200 cc. heptane and 172 g. propylene are charged under nitrogen into a 1100 cc. autoclave. The autoclave is heated to 80 C. and at this temperature the solution of 0.75 g. chromium oxychloride in 50 cc. heptane is injected. After keeping the autoclave in motion for about 20 hours the product is taken out and only small amounts of a propylene polymer, containing about 21% of crystalline product, are isolated.

Example 29 A glass vial containing 2.36 g. (0.012 mole) ZrCl solution of 2.85 g. triethyl aluminum in cc. n-heptane, and two steel balls are charged into a 435 cc. shaking autoclave under nitrogen atmosphere.

The autoclave is heated, while not in motion, to 73 C. and at this temperature 70, g. of a propylene-propane mixture containing 91% propylene are then added. The autoclave is set in motion immediately thereafter so as to break the vial. After a few hours at 80 C., 7.6 g. of polymer are obtained which are fractionated by extraction with hot solvents.

By extraction with hot ether about 30% of the total product, i.e., the amorphous polypropylene is dissolved. In the following extraction with heptane 10% of the product is dissolved, and is formed of a polypropylene containing more than 50% of crystalline polymer. The extraction residue is a highly crystalline polypropylene. The raw product contains therefore about 50% of crystalline polypropylene.

Example 30 Into a 435 ml. autoclave 2 steel balls and a vial containing 4.7 g. (i.e., 0.02 mole) of ZrCL; and 5.7 g. triethyl aluminum in 100 ml. n-heptane are introduced, then the autoclave is heated to 79 C. and 106 g. pure liquid propylene are admitted. Shaking of the autoclave is then started and continued at temperatures in the range 80 to 90 C., while a regular pressure decrease is noticed.

When a pressure decrease is not longer observed, methanol is pumped in and the autoclave is vented 15 N1 of gas being collected. A viscous mass is then discharged, which is purified by treating it as described in the foregoing examples.

72% of the purified product can be extracted with ether and appears completely amorphous when examined under the X-rays. In the following extraction with boiling heptane, a fraction is dissolved which corresponds to 13.8% of the total product. Under the X-rays, this fraction shows a content of crystalline polymer of about 50%; the intrinsic viscosity, in tetralin solution at 135 C., is 0.94. The extraction residue is highly crystalline polypropylene with an intrinsic viscosity of 2.0 (i.e., a molecular weight of about 95,000). The raw product had, therefore, a content of crystalline polypropylene of about 21%.

Example 31 Into a 2150 cc. autoclave are introduced under nitrogen 10 g. of a mixture containing 50% MoCl and 50% MoCl and a solution of 11.4 g. of triethyl aluminum in 500 cc. n-heptane.

Thereafter 365 g. of propylene are added and the autoclave is heated to 100 C., and maintained at this temperature under stirring for about 20 hours. The unreacted propylene is then vented, and the reaction product is extracted from the autoclave and purified by treatment with methanol and hydrogen chloride.

After evaporation of the solvents 115.3 g. of polypropylene are obtained, which are fractionated by hot solvent extraction. The acetone extract corresponds to more than 90% of the total product and is formed of oily, low molecular weight products.

The residue after extraction with acetone is formed by approximately 50% of a polypropylene, which is noncrystallizable and which is extractable with ether, while the rest is a polypropylene which appears crystalline under the X-rays.

Example 32 A glass vial containing 9 g. WCI and two steel balls are introduced into a 2080 ml. oscillating autoclave. The autoclave is then filled with nitrogen and a solution of 11.4 g. Al(C H) in 500 ml. n-heptane is added.

After heating to 70 C., 140 g. of a propylenepropane mixture containing 90% propylene is added and the autoclave is set in motion. After about 10 hours, at 9095 C., the polymerization product is taken out. It appears as a liquid brown mass. After washing with acid and evaporation of the solvent, 38 g. of oily products and 0.5 g. of solid polymer are obtained. The solid product appears approximately 50% crystalline when examined under the X-rays.

Example 33 Into a 435 ml. autoclave two steel balls and a glass vial containing 3.2 g. of solid vanadium trichloride are introduced. Operating as in the foregoing examples 5.7 g. (i.e., 0.05 mole) triethyl aluminum dissolved in 100 ml. heptane are then added. The autoclave is then heated to 83 C., 110 g. of a mixture of l-butene and Z-butene with 70% of l-butene are introduced, and the autoclave is shaken to cause the breaking of the vial. After about 10 hours of shaking at temperatures in the range 86 to 96 C., the autoclave is discharged operating as in the foregoing examples.

42 g. of a solid, fibrous, white substance are obtained;

21.5 g. thereof (i.e.'51.3%) can be extracted with ether A solution of 11.4 g. triethyl aluminum in 400 cc. heptane is introduced under nitrogen into an autoclave of about 2 liters capacity. 220 g. of a mixture of l-butene and 2-butene containing of the former are then added. The autoclave is heated to C. and at this temperature a solution of 4.4 VCl in 100 cc. pentane is added. The autoclave is kept in motion for about 10 hours at temperatures between 75 and C.; the reaction product is then taken out and purified as usual, obtaining 90.2 g. polybutene which are fractionated by successive extraction with hot acetone and ethyl ether. The residue after the extraction with ether corresponds to 27.8% of the obtained polymer and is formed of polybutene which appears crystalline under the X-rays. This fraction has an intrinsic viscosity, in tetralin solution at 135 C., of 1.65.

Example 35 Into a 2150 ml. autoclave 2 steel balls and a vial containing 9.5 g. (i.e., 0.044 mole) ZrCl are introduced. The autoclave is then evacuated and a solution of 45 g. (i.e., 0.1 mole) of a trialkyl aluminum compound (of an average molecular weight corresponding to tridecyl aluminum) in 450 ml. anhydrous benzene is added. The autoclave is heated, without shaking, to 82 C. and 222 g. propylene are introduced. Soon after, shaking is started to cause breakage of the vial, and continued for 14 hours at temperatures in the range 82 to 118 C., while a steady pressure decrease is noticed. After said time 100 ml. methanol are pumped in and a reaction product very much swollen with benzene is discharged. The obtained product contains a large proportion of relatively low molecular weight polymers which are amorphous, whereas only 12% of the total is insoluble in ether.

Example 36 8 g. A1(C3Hq)3 dissolved in 200 ml. heptane and 200 g. of propylene-propane mixture containing 91% propylene are introduced into a 1100 ml. autoclave filled with nitrogen. After heating to 82 C., 3.85 g. VCL; dissolved in 50 ml. n-heptane are injected under nitrogen pressure. The temperature [goes up rapidly to 100 C., while a fall of pressure can be noticed. The autoclave is kept in motion for about 5 hours at a temperature between and C.

The polymerization product is then taken out; it appears as a compact solid mass swollen by the solvent. The product is purified by washing with solvents acidified with hydrogen chloride and then completely coagulated with methanol. 150.8 g. of a solid, white polymer are obtained, which are fractionated by extraction with hot solvents. The results of the fractionation are as follows:

The polymerization product contained therefore approximately 41% crystalline .polymer.

Example 3 7 Two steel balls and a vial containing 3.3 g. (i.e., 0.02 mole) CrCl are introduced into a 435 ml. autoclave and then, under nitrogen atmosphere, a solution of 22.5 g. of

a trialky-l aluminum compound having an average molecular weight corresponding to tridecyl aluminum, in 80 ml. anhydrous benzene is added. The autoclave is heated without shaking to 89 C. and 100 g. propylene are then admitted. Soon after, shaking is started and maintained for 14 hours at temperatures in the range 89 to 105 C. The purification and separation of the polymer is then carried out as in the preceding examples. The polymer which is richer in products of a lower molecular weight contain only 14% of products insoluble in ether, and extractable with hot heptane. When examined under the Xrays this fraction appears approximately as 50% crystalline.

Example 38 Into a 2350 ml. autoclave 2 steel balls and a vial containing 7.8 g. of liquid V01 are introduced. The solution of 45 g. of a trialkyl aluminum (of an average molecular weight corresponding to aluminum tridecyl) in 500 ml. n-heptane is then added.

The autoclave is then heated to 87 C. and 260 g. of butene (containing about 70% of l-butene) are added. Shaking of the autoclave is then started and continued for about hours, while keeping the temperature near 87 C.

Operating as in the foregoing examples 113 g. of a 1-butene polymer are obtained which is found to be almost entirely amorphous. It contains in fact less than 10% of crystalline product.

Example 39 A solution of 17.5 g. AI(C H in 200 ml. n-heptane is introduced into a 2080 m1. autoclave filled with nitrogen. 280 g. of a propylene-propane mixture containing 91% propylene are then added. After heating to 80 C., 2.2 g. V001 dissolved in 50 ml. heptane are injected under nitrogen pressure. The temperature rises sharply to 90 C., while the pressure falls. After keeping the autoclave in motion for about 5 hours, the product is taken out and purified as usual. By coagulation with a large amount of methanol, 90 g. of polypropylene are obtained, which are fractionated by extraction with hot solvents. The following fractions are obtained:

Percent of Intrinsic the total viscosity Remarks polymer Acetone extract 47. 6 Ether extract 31. 5 Amorphous solid. n-Heptane extract..- 11. 8 50% crystalline. Residue 9. 1 Crystalline.

The obtained polymer was therefore approximately crystalline.

Example 40 A solution of 0.02 mole trihexyl-aluminum in 250 ml. heptane, and 80 g. l-butene are introduced in a 1 liter autoclave filled with nitrogen. After heating the autoclave to 90 C., a solution of 1.38 g. (0.008 mole) VOCl in 50 ml. heptane is injected under nitrogen pressure. The temperature rises spontaneously to 95 C. The autoclave is kept in motion for about 4 hours at this temperature; the reaction product is then taken out and the polymer isolated and purified in the usual way. 32.5 g. of polymer are obtained, which is prevalently amorphous; by extracting it with hot ether, 8.8% of it remains as a residue. This residue appears highly crystal-line when examined under the X-rays.

Example 41 7.6 g. of TiCl dissolved in ml. n-heptane are added to 11.4 g. triethyl aluminum dissolved in 50 ml. n-heptane, at 70 C., while stirring. The reaction mixture is then filtered under nitrogen atmosphere through a porous diaphragm G4 (diameter of the pores 5-15 microns) and the solid phase is washed on the filter with a total of 120 ml. of a heptane solution containing 2% of triethyl aluminum. The solid phase is then suspended in 100 ml. n-heptame and introduced, while stirring under nitrogen pressure, into a glass vial which is then sealed. The vial, together with 3 steel balls (1 inch diameter), and a solution of 11.4 g. triethylaluminum in 400 ml. n-heptane are then introduced into a 2150 m1. autoclave. The autoclave is heated to C. and 295 g. liquid propylene are introduced, the autoclave being soon after put in motion, while the temperature is kept between 80 and C. When a pressure decrease no longer occurs, methanol is pumped into the autoclave and the gaseous products are released.

The reaction product is extracted from the autoclave as a nearly entirely solid mass which is purified by the usual method and by treatment with boiling toluene and concentrated HCl. After precipitation with methanol and several washings with methanol, it is filtered and dried. 111 g. of polymer are thus obtained, which correspond to a 37.5% conversion of the employed propylene. More than half of the product (53.7%) is made up of crystalline polypropylene, which may be separated from the noncrystalline product'by extraction with solvents.

Example 42 80 ml. of the solution obtained by filtering the catalyst used in the foregoing example are syphoned into a 310 ml. autoclave, under nitrogen atmosphere. The autoclave is heated up to 80 C., 76 g. liquid propylene are introduced and finally the autoclave is put in agitation. About 6 hours from the start of the polymerization, when a remarkable pressure decrease is no longer observed, methanol is pumped into the autoclave in order to decompose the catalyst, and the gaseous products are then vented. The reaction product extracted from the autoclave appears as a viscous, nearly colorless liquid. It is coagulated 'with methanol to obtain a. solid, gummy product which is treated as usual for its purification. It appears Wholly amorphous under the X-rays.

Example 43 7.3 g. vanadium tetrachloride dissolved in 20 ml. n-heptane are added at 70 C., while stirring, to 11.4 g. of triethyl aluminum dissolved in 70 ml. n-heptane. The reaction mixture, consisting of a liquid phase wherein a brown precipitate is in suspension, is filtered under nitrogen atmosphere through a porous diaphragm whose pores have a diameter of 5 to 15 microns. The solid phase is then washed three times on the filter with 30 ml. each time of a 1% solution of triethyl aluminum in n-heptane. The solid phase is then suspended in 2.50 ml. n-heptane, and, while stirring, it is syphoned under nitrogen atmosphere in a previously deaerated glass flask provided with stirrer, dropping funnel and refluxing cooler. In the flask kept under nitrogen atmosphere, 11.4 g. triethyl aluminum are then added. The temperature of the mixture is raised to 70 C. and 150 g. styrene are added while stirring. Agitation is maintained for 4 hours at temperatures between 70 and 75 C. The flask is then allowed to cool, the catalyst is decomposed with methanol and finally the reaction product is treated with hydrochloric acid. The liquid mass contains in suspension a solid, fiocky polymer which is then separated by filtration.

The solid polymer is made up of two portions, one of which is soluble, the other insoluble, in acetone. The insoluble portion, corresponding to 68% of the whole solid, is found to be highly crystalline, whereas the acetone soluble portion is amorphous.

Example 44 The filtered solution, described in the foregoing example on the preparation of the catalyst, is introduced into a 1000 ml. flask under nitrogen. ml. n-heptane are then added and the flask is heated to 80 C. Next g. styrene are added While stirring. The agitation is continued for 4 hours at temperatures in the range 70 to 75 C. After cooling, the reaction product is treated with methanol and hydrogen chloride. Thus small amounts of styrene polymer (entirely amorphous) are separated from the methanol solution. It is shown thereby that while the little dispersed catalyst, which may be separated by filtration as indicated in the Example 43, yields a prevailing crystalline product, the dispersed portion (which passes through the filter) yields a wholly amorphous polymer.

Example 45 A solution of 12.9 g. triphenyl-aluminum in 250 ml. anhydrous benzene and 235 g. of a propane-propylene mixture containing 91% propylene are introduced into a 2080 ml. autoclave filled with nitrogen.

A-fter heating to 95 C., a solution of 3.8 g. titanium tetrachloride in 40 m1. benzene is injected in the autoclave. The temperature goes up spontaneously to 100 C., and the autoclave is kept in motion at this temperature for a few hours. The reaction product is then taken out and purified as usual; 159 g. polymer are isolated, which are fractionated by extraction with boiling solvents, with the following results:

The raw polymer had therefore a crystallinity, as determined by X-rays measurements, of about 31%. The infra-red spectra of laminae prepared from the ether extract and from the heptane extract indicate the presence in the polymer of monosubstituted phenyl groups.

In a preferred embodiment, the unsaturated hydrocarbon polymerized contains from 3 to 8 carbon atoms.

By amorphous as used herein We mean that state between true solid and true liquid in which matter shows no distinct crystal lattice but does not flow due to its high viscosity.

By state of dispersion as used herein, we mean the degree to which matter consisting of aggregates is diveded up into particles of various sizes ranging from a monomolecular dispersion, as in a true solution, to a coarse dispersion by which we understand a dispersion of particles of a size above a few microns. Intermediate degrees of dispersion comprise matter divided into micelles as in colloidal solutions.

correspondingly, by a finely dispersed state is meant a state wherein the dispersed particles have a size below a few microns, i.e., particles which are prevalently dispersed in the colloidal state or, in the extreme case, true solutions. Inert solvents used for preparing the polymerization catalyst when the same is not prepared in the monomeric unsaturated hydrocarbon, and the conditions used, including the temperatures and pressures used, are the same as disclosed in our aforementioned Italian Patent No. 537,425.

The method of precipitating the polymer with methanol, and of solvent fractionation described in the examples are chiefly intended for establishing the total amount of amorphous and crystalline polymers.

In practice, in the production of commercial polymers, particularly of highly crystalline products, the high molecular weight polymer, spontaneously separated from the solvent, which will only retain the small amounts of oily polymers that may be present, may be simply washed with alcohols to eliminate the enclosed catalyst.

For all those uses where a specially high purity is not required a washing with a hydrocarbon solvent may be substituted for the alcohol washing.

After drying the product will be ready for use.

It will be apparent that various changes and modifications may be made in practicing the invention and, therefore, it is to be understood that the invention is not intended to be limited except as defined in the appended claims.

What is claimed is:

1. A process for polymerizing alpha-olefins selected from the group consisting of propylene, butene-l and styrene directly to a crude polymerizate made up for more than 50% of linear, regularly head-to-tail atactic macromolecules, which process comprises contacting the alphaolefin, in an inert hydrocarbon solvent and at a temperature of from about 60 C. to about C. with a catalyst consisting essentially of the hydrocarbon-soluble portion of the catalytic product prepared by (1) starting with a compound of a transition metal selected from the group consisting of the hydrocarbon-soluble halides, oxyhalides and alkoxyhalides of titanium, vanadium, zirconium, chromium and molybdenum, and (2) mixing said hydrocarbon-soluble compound with an aluminum compound in which at least all but one of the valences of the metal are satisfied by alkyl radicals containing more than four and up to 16 carbon atoms, and the remaining valence, if any, is saisfied by a member selected from the group consisting of said alkyl radicals and alkoxy radicals.

2. The process according to claim 1, characterized in that the catalyst consists essentially of the hydrocarbonsoluble portion of the catalytic product prepared by mixing a hydrocarbon-soluble titanium compound with the selected aluminum compound.

3. The process according to claim 1, characterized in that the catalyst consists essentially of the hydrocarbonsoluble portion of the catalytic product prepared by mixing a hydrocarbon-soluble vanadium compound with the selected aluminum compound.

4. The process according to claim 1, characterized in that the catalyst consists essentially of the hydrocarbon soluble portion of the catalytic product prepared by mixing titanium tetrachloride with the selected aluminum compound.

5. The process according to claim 1, characterized in that the hydrocarbon-soluble catalyst is obtained by (1) mixing the selected hydrocarbon-soluble transition metal compound with the selected aluminum compound in a hydrocarbon solvent, to form a turbid suspension of the product resulting from the action of the aluminum compound on the transition metal compound and which product comprises hydrocarbon-insoluble portions and hydrocarbon-soluble portions, and mechanically separating the hydrocarbon-soluble portions of said product from the suspension.

6. The process according to claim 5, characterized in that the catalyst consisting essentially of the hydrocarbonsoluble portions is separated from the catalytic product obtained by (1) starting with a selected hydrocarbonsoluble transition metal compound in which the metal has the maximum valency corresponding to its position in the Mendele'eff Periodic Table, and (2) mixing said compound with the selected aluminum compound.

7. The process according to claim 1, characterized in that the alpha-olefin polymerized is propylene.

8. The process according to claim 1, characterized in that the alpha-olefin polymerized is butene-l.

9. The process according to claim 1, characterized in that the alpha-olefin polymerized is styrene.

10. The process according to claim 1, characterized in that the catalyst consists essentially of the hydrocarbonsoluble portions of the catalytic product prepared by (1) starting with the selected hydrocarbon-soluble transition metal compound and (2) mixing said compound with an aluminum trialkyl in which the alkyl groups contain from 5 to 16 carbon atoms.

11. The process for polymerizing alpha-olefins selected from the group consisting of propylene, butene-l and styrene directly to polymerizates made up for more than 50% of linear, regularly head-to-tail polymers, which process comprises contacting the alpha-olefins, in an inert hydrocarbon solvent, at a temperature of from about 60 C. to about 100 C., and under normal to slightly elevated pressure, with a catalyst consisting essentially of the hydrocarbon soluble portions of the product obtained by (1) mixing a transition metal compound selected from the group consisting of the hydrocarbon-soluble halides, oxyhalides and alkoxyhalides of titanium, vanadium, zirconium, chromium and molybdenum with (2) an alkyl aluminum compound in which at least all but one of the valences of the aluminum are satisfied by alkyl radicals and the remaining valence, if any, is satisfied by a member selected from the group consisting of said alkyl radicals and alkoxy radicals, to obtain a catalytic product comprising (A) substantially solid, hydrocarbon-soluble portions and (B) hydrocarbon-soluble portions, and mechanically separating the hydrocarbon-soluble portions (B) of the product from the substantially solid, hydrocarbon-insoluble portions (A) thereof.

12. The process according to claim 11, characterized in that the alpha-olefin which is polymerized is propylene.

13. The process according to claim 11, characterized in that the alpha-olefin which is polymerized is butene-l. 14. The process according to claim 11, characterized in that the alpha-olefin which is polymerized is styrene.

References Cited by the Examiner UNITED STATES PATENTS 2,731,452 1/1956 Field et al 260--94.9 2,862,917 12/ 1915 8 Anderson et al 26094.9 2,901,470 8/1959 Gresham 260-93.5 2,905,645 9/ 1959 Anderson et al. 26094.9 2,954,367 9/1960 Vandenberg 26093.7 2,962,451 11/ 1960 Schreyer 26094.9 3,041,325 6/1962 Farnham 26093.5 3,058,963 10/1962 Vandenberg 26094.9

JOSEPH L. SCHOFER, Primary Examiner.

20 HAROLD BURNSTEIN, LESLIE H. GASTON, JOSEPH 

1. A PROCESS FOR POLYMERIZING ALPHA-OLEFINS SELECTED FROM THE GROUP CONSISTING OF PROPYLENE, BUTENE-1 AND STYRENE DIRECTLY TO A CRUDE POLYMERIZATE MADE UP FOR MORE THAN 50% OF LINEAR, REGULARLY HEAD-TO-TAIL ATACTIC MACROMOLECULES, WHICH PROCESS COMPRISES CONTACTING THE ALPHAOLEFIN, IN AN INERT HYDROCARBON SOLVENT AND AT A TEMPERATURE OF FROM ABUT 60*C. TO ABOUT 100*C. WITH A CATALYST CONSISTING ESSENTIALLY OF THE HYDROCARBON-SOLUBLE PORTION OF THE CATALYTIC PROCUCT PREPARED BY (1) STARTING WITH A COMPOUND OF A TANSITION METAL SELECTED FROM THE GROUP CONSISTING OF THE HYDROCARBON-SOLUBLE HALIDES, OXYHALIDES AND ALKOXYHALIDES OF TITANIUM, VANADIUM, ZIRCONIUM, CHROMIUM AND MOLYBDENUM, AND (2) MIXING SAID HYDROCARBON-SOLUBLE COMPOOUND WITH AN ALUMINUM COMPOUND IN WHICH AT LEAST ALL BUT ONE OF THE VALENCES OF THE METAL ARE SATISFIED BY ALKYL RADICALS CONTAINING MORE THAN FOUR AND UP TO 16 CARBON ATOMS, AND THE REMAINING VALENCE, IF ANY, IS SATISFIED BY A MEMBER SELECTED FROM THE GROUP CONSISTING OF SAID ALKYL RADICALS AND ALKOXY RADICALS. 